Apparatus for making metallic bellows



Jan, 17, 195 w. H. GRANT APPARATUS FOR MAKING METALLIC BELLOWS 4Sheets-Sheet 1 Filed Aug. 1'7, 1946 INVENTOR. P511. LIA/W1 Glam z Jan.17, 1950 w. H. GRANT 2,495,059

APPARATUS FOR MAKING METALLIC BELLOWS Filed Aug. l7, 1946 4 Sheets-Sheet2 L3 W Kl INVENTOR.

gnu/(NH. Gram 7;

Jan. 17, 1950 w. H. GRANT 2,495,059

APPARATUS FOR MAKING METALLIC BELLOWS Filed Aug. 17, 1946 4 Sheets-Sheet3 INVENTOR. MZLMMH Gmw'r,

Jan. 17, 1950 w. H. GRANT 2,495,059

' APPARATUS FOR MAKING METALLIC BELLOWS Filed Aug. 1'7, 1946 4Sheets-Sheet 4 vvvvv &

INVENTOR. I/ILLMNH. Giawrv Patented Jan. 17, 1950 UNITED STATES PATENTOFFICE APPARATUS FOR MAKING METALLIC BELLOWS William H. Grant,Cleveland, Ohio Application August 17, 1946, Serial No. 691,216

9 Claims. (01. 153-73) This invention relates to a new and improvedapparatus for making expansible and collapsible hollow walls in theform, for example, of metallic bellows, formed from a tube andcomprising a plurality of coaxial convolutions or folds.

An apparatus and method of this character is shown, described andclaimed in my prior ap plication, Ser. No. 568,038, filed December 13,1944. As there described, thin walled tubes are formed into bellows byexpanding them between separable die rings which form the corrugationswhile subjecting the tube to internal fiuid pressure.

As there shown, and as is frequently practiced, the tubes are formed ofone closed end, and the open end is fitted over a cylindrical projectionhaving a passage leading to the interior of the tube.

It is an object of the present invention to provide means engaging theinterior of the tube for coacting with a contractible gripping meansembracing the exterior of the tube and acting to seal the end of thetube to hold the internal pressure during the formation.

Another object of the invention is to so arrange the sealing means thatas the dies are brought into engagement with the unformed tube blank,the sealing means may be automatically, effectively operated to grip andembrace the end of the tube surrounding the projecting guide withoutdistorting the tube. A related object is to so arrange the partsellecting the gripping and sealing action that the seal is maintainedduring the formation, and which act after the formation and release ofthe pressure, and consequent upon opening of the dies shall be loosenedto release the tube, allowing it to be easily removed.

In said earlier application a comparatively brief description was madeof the operation of such a tube sealing means, and notice was given ofthe intent to file an application presenting the subject matter of thisgripping and closing means.

In the present application is presented a more detailed illustration anddescription of the sealing means shown and described in the priorapplication, and in addition I have shown in the present application twomodified forms of tube sealing means.

All these forms have a common object of simply, effectively andautomatically sealing of the tube when it is placed in position and isgripped by the dies, and which will release the grip allowing theremoval of the tube consequent upon finishing of the tube and theopening of the dies.

More specific objects will become apparent in the following descriptionwhich relates to the accompanying drawings, and the essentialcharacteristics are summarized in the appended claims.

In the drawings,

Fig. 1 is a side elevation of a tube bellows.

Fig. 2 is a plan of die carriers, partly in section, and shown in openposition.

Fig. 3 is a similar view in the nature of a horizontal section throughthe die carriers, showing the closed position.

Fig. 4 is an enlarged sectional view taken on a plane through the axisof the tube, and dies showing the gripping means in closed operativeposition.

Fig. 5 is a sectional view of a modified form of means for closing thegripping ring being taken on a plane indicated by the line 5 -5 of Fig.7.

Fig. 6 is an axial section through the tube and gripping means; and

Fig. '7 is a plan of the same.

Fig. 8 is a modified form in the nature of an axial section through thetube and pressure fluid passage leading thereto with a piston andcylinder arranged to contract the sealing ring.

Referring first to the form shown in Figs. 2, 3 and 4 which correspondsto like parts described in my said prior pending patent application, Iwill refer briefly to the die carriers which are fully shown anddescribed in said prior application.

The carriers comprise frame members I and 2, hinged to a pintle 5carried on a bracket 6 projecting from a frame 1 of a machine, notshown, but which may be of the general nature shown in my said priorapplication. Push and pull rods 8 and 9, hinged at 10 and H to theframes l and 2 serve to swing them from the open position shown in solidlines to the closed position shown in dotted lines in Fig. 2.

A series of pairs of die plates A and B are normally spaced as indicatedin Figs. 4 and 8, and are mounted to move upwardly by the action of theplunger acting on the bottom die C (Fig. 8) to bring the pairs of dieplates together forming the convolutions Tl (Fig. 1) in the tube T beingguided during this closing or collapsing'movement axially along the tubeby pairs of guide rods l4 and I5 in'the frames I and 2, respectively.

Each of the pairs of die platesA and]? are formed with tube embracingrecesses 20, extending half way around thetube and cut away to form acavity into which the folds'of the con- 3 volutions T! are extended. AtT2 (Fig. 1) is a more rectangular fold which may be formed by acomplementary recess as at Di in a thicker pair of die plates D at Fig.4.

Overlapping projections 22 and 23 on the carrier frames l and 2 areprovided with openings 24 for receiving a vertically movable locking pin25 carried on a slide 26, slidable in a rigidly mounted guideway 28, andserving to lock the die carrying members and dies in closed positionduring the formation of the tube as described in my aforesaidapplication.

Projecting into the tube blank T for a distance no greater than thecollapsed length of the corrugated tube, when it is in the form shown inFig. 1, is a guide stud having a passage 3| leading therethrough to theinside of the tube.

The tube T fits slidably over this projection 30. A head member 34 rigidwith the projection 30 is shown as having threads 35 for rigidly gcarrying it in the frame, and for suitable tubular connections, notshown, for the high pressure fluid.

The head portion is shown as having a slight enlargement at 36 which isprovided with a downwardly and outwardly sloping beveled face receivinga tapered ring 4!] split at Al to allow it to contract and tightlyembrace the upper end of the tube blank T when it is forced upwardly bya flange 42 on a collar 44. This collar is slidably fitted over the headmember 36 and is provided with outwardly extending wedge surfaces 48adapted to be moved upwardly by wedge surfaces 50 on wedge blockssecured to the top members of the frame I and 2.

It will be seen that with the tube blank in the position shown in Fig.4, as the die carrier frames are brought together, the surfaces of thewedges 50 will engage the surfaces 48 moving the collar 44 and itsflange 42 upwardly forcing the split ring into its tapered surfacecontracting it tightly around the tube.

This ring is preferably of hard material and may be split on an angle,as shown at Al, and

the amount of contraction required is only a few thousandths of an inchto cause a tight gripping. Thus, the danger of pinching or folding thethin metal of the tube is eliminated.

As the die carriers are swung apart from the position in broken lines inFig. 2 to that shown in solid lines in that figure, the wedge surfaces50 are withdrawn from the surfaces A8, and the sleeve M thus drops,releasing the ring 40, which tends to expand slightly assuring immediateloosening of the upper end of the tube and allowing it to drop free orto be removed easily.

The wedge blocks 50 may be adjusted by loosening and then tightening thescrews to position the blocks toward or away from the center, and thusto increase or decrease the wedging action on the surfaces 48.

As pressure is applied to the interior of the tube, and during theformation of the folds, considerable force is required to counteract thetendency of the tube to slide axially, withdrawing the upper end fromthe gripping means.

More specifically, as the fold is being formed between the upper pair ofdies D and the flange 42, the high internal pressure exerts a strongpull downwardly upon the portion of the tube within the gripping ring40.

Thus, it will be seen that it is important not only to seal the tube toretain the internal pressure, but that to assure formation of the foldthis gripping and sealing must resist a substan-" tial pull downwardlyupon the upper end of the tube. Not only should the tube fit closelyover the projecting stud, particularly at its upper end, but thecontracting action of the ring 40 should actually squeeze the tubebetween it and the ring, and this squeezing action must be without anywrinkling or distortion of the metal of the tube.

Having in mind that the thickness of the tube may be only a fewthousandths of an inch, it is important that the closing action of thisgripping ring should be only a very slight contracting motion, and thatthe split in the ring at 4| should normally be opened only suflicientlyto allow the tube to slidably fit within it, and when in the grippingposition the opening at the split should have only a few thousandths ofan inch clearance.

In the modified form shown in Figs. 5, 6 and '7, greater flexibility andassurance of the tightening of the sealing ring, without necessity forfrequent adjustment, may be attained by the use of rubber or likecushioning blocks effecting the wedge action, as will be described.

Referring particularly to Fig. 6, the split guide ring 40 is movedaxially into its tapered seat by a flange 42 formed on a collar having awedge flange 6| in the form of a ring having a sloping wedge surface. Acorresponding ring is fitted over the head 68 and seats against ashoulder 65, and presents a flange 69 with an upwardly fac ing wedgesurface.

Drawing the wedge ring 60 and its flange 42 upwardly, contracting thesplit sealing ring onto the tube T, may be effected by wedging the twoflange rings 60 and 65 toward each other. In this form I may accomplishthis movement simply and very effectively by using a pair of half rings10 and "H having complementary wedge surfaces engaging the surfaces ofthe flanges GI and 69, and shown as pivotally carried on a pin 15depending from a fixed portion of the frame designated 16.

Each of the flanged half rings 16 and 1| is shown as having anextension, 13 and H3 respectively. the one carrying a pin ?1 forpositioning an expanding spring 18 tending to open the rings, whilepermitting them to be closed to wedgingly embrace the flanges iii andEd.

The upper portions of the frame members I and 2 are shown as carryingbrackets 9| and 92 in which are mounted resilient blocks of rubher orthe like, designated 93 and 94, which in turn bear against flattenedportions 96 and 9'! on the embracing wedge rings 10 and H.

Thus. it will be seen that as the frame members, carrying dies A and Bare brought to the closed position embracing the tube T, that theresilient blocks 93 and 94 will force the wedge ring members It and Hinto close engagement with the Wedge flanges 6! and 69, moving theflange 42 upwardly. and thus forcing the sealing ring 40 into itstapered seat, and. effectively gripping the tube and effecting a seal.

Instead of the arrangement of blocks 93 and 94 positioned to bearagainst the middle portion of the half rings, I may position the blocksto bear against the extensions 13 and M. This is shown in broken linesin Fig. 7. Resilient blocks 93a and 94a may be mounted in bracket members 91a and 92a, movable with the die frame members as are the brackets9| and 92, described.

As liquid under pressure is admitted through the opening 3|, the tubemay be formed, while any desired pressure is being maintained. Afterforming is completed the die carrying frame members, I and 2, swingapart, the closing pressure against the wedge ring members and 'II isreleased, and the lower flanged ring 6| moves axially downwardly,allowing the sealing ring 40 to expand, releasing the grip on the upperend of the tube.

The modified form shown in Fig. 8 comprises an arrangement for forcingthe tapered sealing ring 40 into its tapered seat by the action of apiston and cylinder. As shown, the cylinder comprises a central sectionI00, with a lower removable head member Ill5, a removable packing headcomprising a plate I06, and. a gland plate I08 fitting around a pistonrod I20 which has an axial bore I3I communicating with the bore 3|leading to the interior of the tube '1.

Rigid with the piston rod I20 is an enlarged head portion I25 having areduced extension I24 provided with a tapered seat for receiving thetapered sealing ring 40 which is seated at its fiat lower side againstan inwardly projecting flange I92, corresponding to the flange 42 ofFig. 4.

Above the head portion I25 is shown a double arrangement of packingpiston ring I35 and I36, extending each way from a spacer I31, andclamped by a plate I38 and screws I40 threaded into the head I25.

An additional sealing ring I42 is shown as clamped by a screw held ringI43 to effect a seal between the head and the extension on the pistonhead I40. Thus, it will be seen that the piston which is allowed a veryshort movement may be moved upwardly and downwardly by admitting fluidalternately to the upper and lower sides of the pack I35 and I36 throughpassages not shown. This may be effected under the control of partscooperating with and actuated in consequence to the opening and closingof the die carrying frames.

Having thus described my invention, what I claim is:

1. In a machine for shaping a hollow metal article by internal liquidpressure separable dies for engaging the hollow article, and means forclosing the dies around the article a split ring and a stud adapted toengage a neck portion of the article between them, a tapered seat forthe ring, and means actuated by the first named means for moving thering into its seat consequent on closing of the separable dies.

2. The combination with separable dies adapted to embrace a metal tubewhile forming it in the dies by applying liquid pressure to the insideof the tube, of a stud for projecting into the tube, a split ringadapted to fit over the tube and positioned around the stud, a taperedseat for the ring, and wedging means for forcing the ring into its seatto tighten it upon the tube as the dies are closed.

3. In a tube bellows forming device having separable dies and carriermeans for bringing them together on a tube to be formed, a guide studfor receiving the open end of the tube, a split ring and a seat thereforhaving a conical beveled surface, means connected with the carrier meansfor moving the ring and seat axially of the tube to grip the tubeagainst the stud consequent upon closing and opening of the die carriermeans.

4. In an apparatus for shaping a hollow metal article while applyinginternal liquid pressure, a cylindrical member projecting into an openneck of the article, a split metal ring embracing the neck and a fixedtapered seat therefor surrounding the said cylindrical member, separabledies and carrying means therefor, means for bringing the dies together,means for applying power to 5. The combination with separable dies forembracing a metal tube during forming by applying liquid pressure to theinside of the tube, of a stud projecting into the tube, a split ringaround the stud and arranged to fit over the end of the tube, a taperedseat for the ring rigid with the stud, and movable wedging means forforcing the ring into its seat to tighten it upon the tube as the diesare closed, means carrying the separable dies and having surfaces foractuating said wedging means.

6. In a device of the character described, the combination of acylindrical stud adapted to receive the open end of a tube to be formed,a concentric tapered seat rigid with the stud, a split tapered grippingring fitted into the tapered seat and adapted to embrace and gripthetube be tween it and the cylindrical stud, a plurality of dies arrangedin pairs and carrier members for the dies adapted to bring them intoengagement with the tube and to open to release the tube, a membermovable axially of the tube and stud, and wedging surfaces carried bythe die carriers for moving said last named member and the taperedgripping ring toward gripping engagement upon closing of the dies.

'7. In a device for forming tubular bellows be tween a series of pairsof separable dies under hydraulic pressure within a tube blank andincluding radially movable die carriers, of means for projecting intoand fitting one end of the tube, a split ring surrounding saidprojecting means, a tapered seat for said ring rigid with saidprojecting means, said ring having a complementary tapered surface, anaxially movable member for urging the ring into its seat and having awedging surface, wedging elements mounted on the die carriers andadapted to act when moved radially toward the tube to seat the ring intube gripping engagement.

8. In a device of the character described, the combination of aprojection adapted to fit into the end of a tube to be formed byinternal hydraulic pressure, an annular seat surrounding the projectionand rigid therewith, a split gripping ring having a surface fitting theannular seat and fitting over the end of the tube, an axially slidablecollar engaging said ring and having outwardly projecting slopingsurface, a corresponding collar having a surface sloping toward thefirst mentioned collar, a divided wedge ring having complementarywedging surfaces for engaging the last two mentioned sloping surfaces,means for movably supporting said divided wedge ring members, separabledie carrier members and resilient means interposed between them and saidrings effective to cause the wedging and gripping action consequent uponclosing the dies into tube-forming position.

9. In an apparatus of the character described, the combination of aprojection adapted to fit into the end of a tube blank, a split ringsurrounding the projection for receiving the tube end, a means forengaging and contracting the split ring to effect a seal and to effect agripping action resisting longitudinal motion, separable dies forembracing the tube, carriers for the die members for bringing themtogether around the tube, and means connected with and actuated bymovement of the carriers for operating the means for engaging andcontracting said ring file of this patent:

UNITED STATES PATENTS Name Date Krammer Sept. 19, 1916 Farmer Dec. 30,1924 Clifford Oct. 30, 1928 Grant Jan. 21, 1936

